PURPOSE: To perform the title isomerization by bringing a dichlorotoluene isomer mixture into contact, in the presence of hydrogen, with a catalyst comprising the acid-type modification of boron- or iron-contg. zeolite and Re component and/or Ag component and pref. furthermore, F and/or P component(s).
CONSTITUTION: The objective isomerization can be performed by bringing a dichlorotoluene isomer mixture into contact, in the presence of hydrogen at 250-450°C, with a catalyst comprising (A) the acid-type modification of boron- or iron-contg. zeolite (pref. of mordenite type) and (B) Re component and/or Ag component. The boron or iron content of the component A is 0.05-1.0wt.%. The Re or Ag content of said catalyst is 0.05-1.0wt.%; the Re has been incorporated in the catalyst through impregnation or kneading, the Ag through ion exchange or impregnation technique. Said catalyst is pref. further incorporated with F and/or P component(s). With the present method, the isomerization can be made in high selectivity with side reactions inhibited.
MANGAYA YASUHIRO
IWAYAMA KAZUYOSHI
